Friction shock absorbing mechanism



A. P. WITHALL FRICTION SHOCK ABSORBINGIECHANISM Aug. 30, 1932.

Filed Sept. 10. 1328 2 Sheets-Sheet 1 Aug. 30, 1932. A. P. wlTHALL 1,874,403

FRICTION SHOCK ABSORBING IECHANIISM` Filed sept. 1o, 192e '2 sheets-snaai 2 Piaf/wf ffx, /f .63E 4 lllllll! Patented Aug. 30, 1932 UN ITI-1D, :STATES FFICE .ALBERT r, wrTHAiLL, or CHICAGO, IIQLlINQIs, assicurer:

CHICAGO, ILLINOIS, AA GQRPORATILQNi-OF' DEI-Aven' f y -FRIcTIoN 'si-aocx: Aiasi'irtiar NeiL MECBVANIJSI p This invention relates to improvements vin friction shock absorbing mechanismsgi One obj ectof the invention is to provide a friction shock` absorbing mechanism n especially adapted for railwaydraft riggings affording free spring action during the first part of the compression stroke, including-av shell and having laterally projecting anchoring flanges thereon engaging limiting shoulders on the cage. A more specific object of the invention is to provide a mechanism of the character indicated including a spring cage; a friction shell telescoped within the cage; interior liners anchored to the shell :and havingflaterally outwardly projecting flanges at the'rear ends thereof exterior to the'shell Vand extending outwardly beyond the salneand having shouldered engagement with the cage-tol limit outward movement ofl the shell with respect thereto; friction means cooperating with the liners including friction shoes 'and a wedge spreading member; and spring resistance means withinthe cage opposing the relative movement of. the shell with respectthere`to and also 'yieldingly resisting relative movement of the friction means and shell'.- f

Other objects ofthe invention will more clearly appear from the description and claims hereinafter following. f

In the drawings forming apart of this specification, Figure V1 is a horizontahlong'itudinal'sectional view of a portion of arailway draft rigging illustrating my improvements in connection therewith. FigureZ is a front end elevational view of my improved shock absorbing mechanism, proper: Figure 'Sfis a' transversel vertical sectionalsview co1"- vresponding substantially to the line 3:-3 of Figure 1. Figur'el is a vertical longitudinal underframe, to. the inner sidesof `which are securedfront stop lugs 11``111and rear stop AlugslQ--lQ The inner end portion'of the' coupler` shank is--designate'd by 13, to which i -i's connected-the usual yokemember My improved friction shock absorbing mechav'nisl'n `and a front mainfollowerl' aredis- -posed within theyoliefthe yoke andparts *therewithiriv being supported by .the -usual u" detachablesaddl'e plate 16 secured tothe bot- 'ftom flrilngeslofthe draft sills-"by bolts,- "as a- I My improved shockabs'orbin'g mechanism, proper, comprises, broadly, a spring cage .A afriction shell B, which is connectedthereto for relative movement; `a mainspring folflowerC; amain spring resistanceD ay pair idw-1r. mim, me;V o1' lsectionalgyiewA of the 'front portion of my J Aimproved shock i absorbing mechanism, Vcori -responding substantially to the yline 44-of Figurel.` And Figure 5V isa detail perspecftive view of a liner employed in connection withi m-y'improved' mechanism. Y. 1 i .l i In said drawings, 10;-10 indicate channel shaped center ory draft sills of'a ra-ilwaycar of liners -E-E, which' also serve as the means `to anchorthe'friction shell to the cage two `friction wedge shoesF vand G a wedge block H; and a retainer bolt J. l A' u The spring cage A` is inthe'formy of 'a substantially rectangular box-like member,1havingi longitudinally extending, spaced side walls 17-17 horizontally disposed spaced top and bottom Wal1s18-'18 and a ,transverse 'rear endwall 19,"` VTheend wall 19 cooperates with :thea stop. lugs'12 inV the` manner ofthe f 'usual' rearjfollower, As most clearly shown :in Figures 3 and ll,the side walls 17 ,extend vfor'wardly'l'of, the top. and bottom walls, thereby providing top and bottom openings -20in1the Vspringcage, for appurpose hereinafter pointed out. At the forward Vend portions, the; side `walls 17 are inwardly offset, as indicated at'` 214-21, i thereby presenting transverse vertical front limitiniiwallsec'- tions 224-22?V which cooperate Withftheian- U5 through `tlfie spring follower C, the latter notched at the front ends, as indicated at 24, to facilitate assembling of the spring follower in the cage.` The friction shell B is `of sub-,-

stantially rectangular outline in cross section and, as shown, is telescoped withinthefront end portion of the spring cage' A, being disposed between the inwardly efl'setv wall sec-- tions 21-21 thereof. The friction shell B is providedy with spaced side walls 25-25 and ltop and bottom walls At'its opposite sides, the shell B is provided with top and bottom longitudinally' extending guide ribs 21-27, which engage within guide grooves A28-28, provided at the top and bottom portions.r of the side wall sections 21 of the cage A.

As willbe evident, the friction shell B is thus limited to movement longitudinally of the mechanism bythe guide ribs 27 which prevent vertical displacement ofthe friction shell with respect tothe spring cage and by theV side walls of the friction shell which engage between the wall sections 21 of the springl cage. Inward movement of the friction shell with respect to the spring cage is limited bv the rear end of the shell coming into engagement with'the inner end walls yof theI openings 20 provided in the top and bot'- tom walls of the cage A.. The side walls 25 of the friction shell are provided with seats 29-29 which are adapted to receive holding means on the liners E to prevent longitudinal `movement of the liners with respect to` the shell. The spring follower C which is diswithin the spring cage, is in the form of a relativelj7 heavy substantially rectangular plate cut away at opposite sides', as shown in Figure 3, to prevent curved end faces. The opposite sides of the spring follower C are provided withv notches 30-30, within which the ribs 23 of the spring cage engage, thereby guiding the spring follower forV longitudinal movement. Y

The spring resistance D comprises a central spring element composed of `an inner coil 31 and a heavier outer coil` 32 and four additional spring elements disposed aboutv the central element, each additional spring element also comprising a relatively light inner coil and a heavier outer coil. The four outer spring elements are disposed in the corners of the spring cage and have their vopposite ends bearing respectively on the endwall 19 of the "cage and thefinner side of the spring follower C'. Thefouter coil ofthe central spring member also has its opposite ends bearing on the 'end walt 19' and the spring follower C'. The inner coil of the central spring extends ward movement with respect to this coil.

The liners E are disposed at opposite sides of the friction shell B ,each liner being provided with'a, central lateral enlargement 35 o-n the outer side thereof engaging within the corresponding seat 29 ofthe shell. The enlargement 35 substantially fits this seat so that the liner will be detach-ably fixed to the wall of the friction shell. On the inner side, each liner is provided with a longitudinally disposed friction surface 36 of substantially V- shapefas shown most clearly in Figures 3 and V5. IThe two opposed friction surfaces 36 of th eliners arey preferably converged inwardly of thev mechanism, as shown in Figure 1, to provide for a differential action. At the inner end', each liner is provided with a laterally outwardly projecting flange 38 which engages between the inner end of the friction shell B and the spring follower C. The fianges 38 of the liners are of such a length that they protrude beyond the sides of the friction shell and engage with the wall sections 22' ofthe spring cage to positively limit outward movement of the friction shell.

The friction shoes F and G are disposed at opposite sides ofthe friction shell and are of similar design except as hereinafter pointed out. Each shoe is provided with a longitudinally disposed V-shaped friction surface 39 cooperating with the friction surface 36 of the liner E at the same side of the friction shell. On the inner side, each shoe is provided witha lateral enlargement 40 having a wedge face on the front side thereof. The wedgeface of the friction shoe F is indicated Yby 41 and that of the shoe G by 42. As shown, the wedge face 42 is disposed at a keenwedge-acting angle with respect to the longitudinalaxis of the mechanism, while the wedge face.y 41 of the shoe F is disposed at a relatively blunt releasing angle with respect to said axis. .Both wedge faces 41 and 42 are of V-shape section, as shown, to cooperate with similar wedge faces on the wedge block H.

The inner ends of the friction shoes F and G bea-r directly on the spring follower C, the spring follower being provided with forwardly projecting flange portions 43 which engage the inner ends of the friction shoes, .f

while the main body portion of the spring follower bears on the flanged inner ends of the liners. As most clearly shown in Figure 3, the friction shoes are provided with top and bottom inwardly projecting flanges 44 at j rs1-,annua -the inn'ergnds thereof, `which arefprovided with reinforcingwebs 45.y The webs 45am cutaway, as shown, so as to clear the central coil 31 of thespring'resistance'. At the-top and bottom, the springfollower C is provideri-with lugs'46-46 which engage between the innerA ends of the friction shoes and serve to center the parts during assembling of the fm'echanism. The front end portionV of the coil p31-, cooperates with thev Venlargements of the friction shoes, a spring follower disc47 being interposed between the front end of this coil` andthe enlargements on the shoes.,

The wedge block H is rovidedwith a .slightlyl curved front endaceA which' bears directly on th-e inner side of the main follower 15. At the inner end, the wedge block is provided with a pair of V-shaped wedge faces 48 and 49 lon the oppositeV sides thereof, the

lwedge g face 48 being-inclined at a relatively Vbluntwedge-acting angle'to properly cooperate with thewedge face 41 of the friction shoe F, while thejwedge face j49 isdisposedjat a relatively keen wedge-actingangle to coop- .crate with the wedge' face 42 of thej friction shoe G. i y Y i The mechanismisgheldassembled .and of Aover-all uniform length `byzthe retainer bolt J which hasthe head thereof disposed within `the hollow b'oss 34 atthe inner end of the springcage and has the nut at the opposite end disposed within an opening provided in the wedge block H, the shank` of the bolt eir- .tendingthrough the coill spring I31 .i and an .by compensatingfor` wear of the friction and wedge faces ofthe mechanism. It isffurther pointed out that, dueto the spring 31 being under compression, the friction' shoes are yieldingly urged laterally outwardly by engagement with the wedge blockgand hold the liners seated against the sidewalls of they friction shell,l thereby maintaining the enlargements 35 in anchored relation to the seats 29.

In assembly my improved shock absorbing mechanism, the four outer members of the main spring resistance, together with the coil 32, are first inserted within the spring cage through the open front end thereof. The spring follower'is then inserted lengthwise, laterally, through the opening 20 of either the top or bottom wall of the cage, the spring at this time being placed under a slight compression so as to permit the free insertion of the follower. The spring follower is then rotated to transverse position, alining the sel'nbled` with the v friction shell, engaging 1; y the enlargements 35 thereof within theseats i openingu33 of "the, spring f follower and the friction shoes., :wedge `block and spring foli, hatches" 30- with the ribs-23, .After the-fol'- a lower has been thus assembled, the'ffriction shell Bisinserted between `the sidewall sections 21 of theV cage and the liners are as- 7o 2 9 and-,the flanges 38 in back of theshell, `disposing the samebetween the inner end ofthe shellV and the-'follower C. At the same time, the outer ends of the flanges 38 .will be er1-- Vgagedwin back of the limiting wall sections i 22 of the cage. As will beevident, when the parts have been thus far assembled, the spring i follower vC 'will-erbe" forced inwardly .of the cage a sullicient distance toengage the notches w30 with the ribs 23, 'so that the spring follower will be locked,V within the cage. The inner coil 31 ofthe spring resistance is neXtplaced in position by inserting thesame through the lower disc are then placedin position and the parts secured bythe retainer bolt J.

The operation of my improved' shock absorbing mechanism, assuminga compression stroke, is'as follows: The wedge block H will be forced inwardly ofthe springcageA `upon ,rela-tive.l movement f of the front follower 15 andthe spring cage,andva: `wedging action will :be set up between the wedge block and f the frictionshoes, thereby forcing'the latter apart into tight frictional engagement with the friction surfaces ofthe liners which are anchored to the frictionshell. Inward movement of the friction shoes will be resisted by 10 'the-coil131offthe' main spring engaging the follower disc 47 and byth'e remaining members of the main spring resistance which engage the main spring follower C bearing on the inner "ends'of the shoes.'v vDue tothe great amount of friction created between the friction shoes and the friction surfaces n of 4the shell, the shell will be forced inwardly in .unison with lthe wedgeblock and friction shoes duringtherstpart of the compression .-1.10

ystroke of themechanism and compression of will `be effected. f I l Inward `movement of the frictionshell willv continueuntil thetransverse endwallsof the openings .20 in the topi andf bottom walls of the'spring cage arze'engaged by the innerV end of the friction shell, whereupon movement of the shell will be Uositivelyarrested, thereby 'compellingrelative movement of the friction system comprising the wedge block and friction shoes, with respect to .the friction shell, during the` remainder of the compression stroke. During the Vrelative movement of the friction shoes and friction' shell, all of the members ofthe spring resistance will be com- -all of the coilsof'the main spring resistance pressed'. fL f y whereupon the 'expansive-action lof the main 13 cage and outward movement of the wedge willbe limitedby the retainer bolt J, thus determining the normalfull release position of the friction shoes Vwhich are urged out- Wardly by the coil 3l ofthe main sprmg resistance after movement -arrested.` y

From the preceding description, taken in connection .withthe drawings,it will be evident that I'have provided exceedingly simple of the shell has been and efficient means for anchoringithe friction shell of my improved' shock. absorbing mechanism to the spring cage,VV the detachable liners being employed for this purpose and being held engagedand interlocked with the friction shellby the spreading action ofthe spring urged friction wedge system.- In addition to holding the parts assembled,the retaining means-,comprising the vflanges 387er' the liners,'also serves to' interlock the. spring follower'v with the spring cage so as to prevent removal or accidental lossv of the same by displacingthe spring follower inwardly of the openings through which the same'i's inserted within the spring cageandi maintaining the same in that condition. Y.

I have herein shown and described what I now consider the preferred manner of carrying out my invention, but the same is merelyV illustrative and 'I contemplate all changes and modifications that-come within the scope of the claims appended hereto. Y

I claim: f

1. In a friction shock'absorbing mechanism, the combinationv with aspring cage lhaving top,vl bottom and side walls, said side walls being extended forwardly ofthe top and bottom walls; of a friction shell disposed between saids'ide walls and'liaving top and bottom guide'ribs at oppositesides thereof, having shouldered engagement with the ex.- tended side walls of the cage to -limit relative movement ofthe shell and cage to a direction e .lengthwise of the mechanism; means for anchoring the shell "to the cageproviding a lost motion connection therebetween; friction means cooperating with the shell including Lavagna spring follower may be inserted; liners secured to the friction shell, said liners having idanges interposed between the friction shell and spring followerand having shouldered engagement with the cage, thereby limiting 'outward movement'of the spring follower vand maintainingthe same in position inwardly of the openings'in the shell to hold and friction shoes.

. 3.1In a friction shock absorbing mechanism, the combination with a spring cage open at one end and having spaced side wall members at said open end inset from-oppo- 'sitesides of the cage, said inset wall members forming interior retaining shoulders at their inner ends; of a friction shell telescoped 'within the Iopen end of the cage and being confined against lateral displacement and guided forv movement lengthwise of the mechanism between said side walls; interengaging means on said side wall members and shell holding said shell against vertical displacement; abutment means on the cage cooperating with the inner end of the shell to limit longitudinal movement of the shell and cage with respect to'each other to less than Vthe full compression stroke ofthe mechanism; means for anchoring the shell to the cage, including interior liners'detachably secured to opposed side walls of the shell, said liners having right angular,l laterally outwardly projecting flanges at their rear ends overhanging the inner end of the shell and projecting laterally outward thereof and having shouldered engagement at their outer ends with the shoulders of the cage to limit outward movement of the liners and the shell; friction shoes having sliding frictional engagement with the liners; a wedge block having wedging engagement with the shoes; and spring resistance vmeans within the cage yieldingly opposing inward movement of the shell and shoes.

vInvwitness that I claim the foregoing I haveV hereunto subscribed my name this 8th day of September, 1928.

Y ALBERT I). WITHALL.

a wedge block and friction shoes; ands'pring resistance means within the cage opposing movement of the friction shell and friction means inwardly of the cage.

2. In a friction shock 'absorbing mechanism, the combination with a'sp'ring cage; of a friction shell telescoped within the front end of the cage, said shell and cage having limited relative movement; a spring follower disposed within the cage inwardlyv of the friction shell, certain'walls *ofthevr cage being provided with openings through lwhichl the 

